HD44780 Compatible - suggestions

megabyte · Post by **megabyte** » August 8th, 2006, 3:35 pm

Hi guys,

I've already had a HD44870 XiamenOcular 2x16 LCD before, but because of faulty wiring (ouch) i got fried.
Today I bought a bigger 4x16 LCD for 50 ? (I know, it's really expensive, but there's nothing on the Dutch eBay) from a local store, and was hoping to do this:

- Make it parallel
- Wire up the backlight
- Make a nice case with pots
- Not fry it

I was thinking, could I do something more, like connect some switches to it or make it serial through my PIC (16F84)?

Already drooling about the Winamp spectrum analyser,
megabyte,
Den Haag, Netherlands

_X7JAY7X_ · Post by **_X7JAY7X_** » August 8th, 2006, 3:47 pm

Yes you could use a PIC to make it serial. Have you done any PIC programming before?

There are several PIC projects on here to build your own, but none use the 16f84.

J

megabyte · Post by **megabyte** » August 8th, 2006, 3:49 pm

_X7JAY7X_ wrote:Yes you could use a PIC to make it serial. Have you done any PIC programming before?

There are several PIC projects on here to build your own, but none use the 16f84.

J

Yes, I normally use C, but can also _kinda_ understand assembly.
I think I've also got a 16F627A lying somewhere.

Post by **mattcro** » August 10th, 2006, 5:50 pm

PIC16F627/628 is the one to go for (Jay and I used it). PIC16F84 doesn't have a serial port built in so it's not so good for this project.

I have buttons on my LCD that can be used to control Winamp or whatever. Photos and info in this thread.

I used C for my project. I am lucky to have occasional use of the HiTech PICC compiler which is pretty powerful (and very expensive, unfortunately). There's a free "lite" version which supports a few PICs including 16F627, 16F84A and 16F877. My code (download here could be ported to other compilers with a bit of work.

You could try programming your PIC with Jay's or my code just to see how it all works, then try to develop your own code.

_X7JAY7X_ · Post by **_X7JAY7X_** » August 10th, 2006, 6:59 pm

If they are pin swapable (628 and 627) I can probably recompile for the 627. It should only take me a few minutes to do this. I think the only difference is the amount of memory, which could be a problem.

J

Post by **mattcro** » August 10th, 2006, 11:22 pm

Yeah, there's only 1K words of program memory in the 16F627, which is a bit on the small side for a full implementation of the LCD commands. Other than that I think they are identical.

I'm pretty sure my code is under the 1K mark, but probably not by much, and I have only implemented the main common commands.

megabyte · Post by **megabyte** » August 14th, 2006, 8:14 pm

Thanks for suggestions.
I am a bit more familiar with Basic Stamps, because I have a quite good interface board for it. Is there any program availible for it? If not, do you think I would be able to port the C source to the Basic language? I'm quite good at both.
Also, I've got two additional pins on my LCD named A and K, which I think are supposed to be the backlight power source. Am I right.?

_X7JAY7X_ · Post by **_X7JAY7X_** » August 14th, 2006, 9:16 pm

There are no BS firmware that I know of. There is another thread in the Discussion topics similar to this. My code is written in Basic. I can send it to you if you want to take a look at it. A and K are anode and cathode. They are power for the LED but be careful. You may need a current limiting resistor attached to the backlight or it can burnout.

J